Answer:
A: Is constant irrespective of mass of the gases
Explanation:
Avagadro's number, denoted by nA, is a number that represents the units in one mole of any substance. The number is 6.02214076 × 10²³ and the units can be atoms, molecules, ions, formula units etc.
That is;
1 mole of a substance = 6.022 × 10²³atoms, molecules, ions, electrons etc.
It is important to note that the Avagyadro's number is constant irrespective of mass of the gases that are involved.
Intramolecular forces of attraction are important in holding large molecules together.
a. True
b. False
Answer:
False. Intermolecular forces of attraction are important in holding large molecules together.
Explanation:
Within a molecule, atoms are held together by intramolecular forces. That is, intramolecular forces are the attractive forces that hold the atoms or ions that make up chemical substances (elements and compounds) together, forming a chemical bond.
On the other hand, intermolecular forces are those that act on different molecules or ions and that make them attract or repel each other. In other words, intermolecular forces are those that occur between the different molecules of a compound, and cause these molecules or ions to attract or repel each other.
So, intermolecular forces of attraction are important in holding large molecules together.
Kristy finds the mass of an object to be 20 grams and the volume to be 10 mL. What is the density of the object? (don't send me links, just give a straight answer)
In what form is energy that is NOT used for life processes released from living things?
1. Thermal energy
2. Chemical energy
3. Light energy
4. Sound energy
Answer:
Correct answer would be Option 2, Chemical Energy
Hope this helps!
how old was the oldest animal fossil
help thx
Answer:
the Rhyniognatha hirsti
Explanation:
at age 400 million years old
Calcium has 6 different isotopic forms, listed with their fractional composition values, 40Ca-0.96941; 42Ca-0.00647; 43Ca-0.00135; 44Ca-0.2086 ; 46Ca-0.00004; and 48Ca-0.00187. Identify the most and least abundant isotopes of calcium.
Answer:
The most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca
Explanation:
The mass, in percentage, of eah isotope of Calcium is their fractional composition multiplied by 100:
40Ca-0.96941*100 = 96.941% of ⁴⁰Ca
42Ca-0.00647*100 = 0.647% of ⁴²Ca
43Ca-0.0013*100 = 0.13% of ⁴³Ca
44Ca-0.02086*100 = 2.086% ⁴⁴Ca
46Ca-0.00004*100 = 0.004% ⁴⁶Ca
48Ca-0.00187*100 = 0.187% of ⁴⁸Ca
That means the most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca
The table shows the recipe and the available ingredients for making the maximum possible number of sandwiches.
Making Sandwiches
Recipe for One Sandwich:
2 cheese slices, 1 ham slice, 2 bread slices
Ingredients Available:
12 cheese slices, 10 ham slices, 12 bread slices
If the ingredients represent reactants of a chemical reaction, which of the following represents the leftover reactant?
A. 2 ham slices
B. 4 ham slices
C. 2 cheese slices
D. 4 cheese slices
Answer:
B. 4 ham slices
Explanation:
A chemical reaction involves one or more substances known as reactants combining chemically to give one or more substances known as products.
Reactants in chemical reactions combine in definite mole or mass ratios to give products. Therefore, when one substance is present in excess of what is required to combine with another to form products, that substance is known as the excess reagent. The other substance which is present in a smaller amount and which when used up, the reaction stops is known as the limiting reagent.
From the illustration of the sandwiches in the question, the recipe for one sandwich represents the chemical equation of a reaction. The equation form is given below:
2 cheese slices + 1 ham slice + 2 bread slices ---> 1 sandwich
The ratio of the reactant is 2 : 1 : 2
From the available ingredients, 12 cheese slices, 10 ham slices, 12 bread slices.
12 cheese slices will require 6 ham slices and 12 bread slices to produce 6 sandwiches.
However, since there are 10 ham slices, 4 ham slices will be left over unused. This is the excess or leftover reactant.
Answer:
B. 4 ham slices
Explanation:
Got it right on the test
A small coffee cup calorimeter contains 28.0 g of H2O at 19.73 oC. A 2.05 g sample of a metal alloy is heated to 98.88 oC and then placed in the water. The contents of the calorimeter come to a temperature of 21.23 oC. What is the specific heat of lead
Answer:
1.104 J/g°C
Explanation:
Using Q = m × c × ∆T
Where;
m = mass of substance (g)
c = specific hear capacity (J/g°C)
∆T = change in temperature (°C)
For a colorimeter,
Q(water) = - Q(metal)
m. c. ∆T (water) = - m. c. ∆T (metal)
According to the information provided;
For water:
m = 28.0g
c = 4.184 J/g°C
∆T = (21.23 - 19.73°C)
For the metal:
m = 2.05g
c = ?
∆T = (21.23 - 98.88°C)
m. c. ∆T (water) = - m. c. ∆T (metal)
[28 × 4.184 × (21.23 - 19.73°C)] = -[2.05 × c × (21.23 - 98.88°C)]
[117.152 × 1.5] = -[2.05 × c × (-77.65)]
175.728 = -[-159.1825c]
175.728 = 159.1825c
c = 175.728 ÷ 159.1825
c = 1.104
c = 1.104 J/g°C
A hot air balloon has an air vent that keeps the air pressure inside and outside the same. Allen observes that a hot air balloon rises up when the gas molecules inside it are heated. Which
of the following laws is used to understand the behavior of the gas and why?
a) The high temperature brings the gas molecules closer together according to Charles's law because this law describes how a gas will behave at constant pressure
b) The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.
c) The high temperature lowers volume according to Boyle's law because this law describes how a gas will behave when the number of moles remains constant.
d) The high temperature ralses volume according to Boyle's law because this law describes how a gas will behave when the number of moles remains constant.
Answer:
B - The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.
Explanation:
Charle's Law describes the relationship between temperature and volume, where increased temperature leads to increased volume. When volume is increased, that means the gas molecules are more spread apart and have more random motion. Therefore, the answer is B.
The high temperature causes the gas molecules to spread apart according to Charles's law because explain how a gas, behave at constant pressure.
What does Charles law state?The physical principle called Charles' law which states that the volume of a gas equals a constant value many by its temperature as measured on the Kelvin scale.
Volume regaled by a clinched amount of gas is directly proportional to its temperature and pressure if remains steady.
Thus, option "B" is correct, the volume of a gas equals a constant value.
To learn more about Charles law click here:
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Gamma rays have the highest frequency among all common electromagnetic radiations. It means the gamma rays have the highest energy and the longest wavelength
Answer:
yes
Explanation:
cos of high electron transfer
A molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor
a. True
b. False
Answer:
True
Explanation:
Hydrogen bonding is a type of intermolecular interaction that occurs when hydrogen is bonded to a highly electronegative atom.
We define the term ''hydrogen bond donor'' as the molecule that supplies the hydrogen atom in the hydrogen bond.
Hence, it is true that the molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor
Waves are generated when energy passes through causing them to move matter through ____ ?
Answer:
sending heat waves and vibrations
Describe the buffer capacity of the acetic acid buffer solution in relation to the addition of both concentrated and dilute acids and bases. Reference the results in Data Tables 1,2,3, and 4 in your answer.
Answer:
The more concentrated acetic acid buffer has a better buffer capacity because requires more moles of acid or base to change the pH than a more diluted acetic acid buffer.
Explanation:
Buffer capacity is defined as the moles of an acid or base that are needed to change the pH of a buffer in 1 unit.
A more concentrated solution of acetic buffer contains more moles of the acid per liter of solution. A solution that contains more moles of the acetic ion or the acetic acid requires more moles of base or acid to change the pH, that means:
The more concentrated acetic acid buffer has a better buffer capacity because requires more moles of acid or base to change the pH than a more diluted acetic acid buffer.
Refer to your completed Table 1d of the recitation guide of ionic compound naming rules to determine whether this statement is true or false. A Roman numeral in a compound name tells you how many of that ion appear in the formula. Select one: True False
Answer:
False
Explanation:
Roman numerals are seen in the names of several compounds. They often appear immediately after the name of central atom in the molecule.
These Roman numerals are used to depict the oxidation state of the central atom in the molecule and not to show how many of that ion appear in the formula.
For instance, in carbon IV oxide, the Roman numeral IV shows that the central atom in the compound-carbon is in the +4 oxidation state.
5.96 g of ammonia reacts completely according to the following reaction:
2 NH, (g) + Co, (g) → CN,OH, (s) + H20 (1)
(a) What is the theoretical yield of urea (CN,OH,) for this reaction?
(b) If 13.74 g of urea are produced, what is the percent yield for this equation?
please show work, will give brainliest
Explanation:
this explanation may help u to understand:)
In this lab, you will be making solutions of potassium permanganate (KMnO4), which has a formula weight of 158.04 g/mole. Remember to show your calculations and include tne Correct unnits in your answers
a) How many grams of KMnO4 would you need to make 1 L of a 2M solution?
b) How many grams of KMnO4 would you need to make 350 mL of a 0.75 M solution?
c) How many grams of KMnO4 would you need to make 80 mL of a 0.01 M solution?
Answer:
A. Mass of KMnO₄ = 316.08 g
B. Mass of KMnO₄ = 41.49 g
C. Mass of KMnO₄ = 0.13 g.
Explanation:
A. Determination of the mass of KMnO₄
We'll begin by determining the number of mole of KMnO₄ in the solution. This can be obtained as follow:
Volume = 1 L
Molarity = 2 M
Mole of KMnO₄ =?
Mole = Molarity × Volume
Mole of KMnO₄ = 2 × 1
Mole of KMnO₄ = 2 moles
Finally, we shall determine the mass of KMnO₄. This can be obtained as follow:
Mole of KMnO₄ = 2 moles
Molar mass of KMnO₄ = 158.04 g/mole
Mass of KMnO₄ =?
Mass = mole × molar mass
Mass of KMnO₄ = 2 × 158.04
Mass of KMnO₄ = 316.08 g
B. Determination of the mass of KMnO₄
We'll begin by determining the number of mole of KMnO₄ in the solution. This can be obtained as follow:
Volume = 350 mL = 350/1000 = 0.35 L
Molarity = 0.75 M
Mole of KMnO₄ =?
Mole = Molarity × Volume
Mole of KMnO₄ = 0.75 × 0.35
Mole of KMnO₄ = 0.2625 mole
Finally, we shall determine the mass of KMnO₄. This can be obtained as follow:
Mole of KMnO₄ = 0.2625 mole
Molar mass of KMnO₄ = 158.04 g/mole
Mass of KMnO₄ =?
Mass = mole × molar mass
Mass of KMnO₄ = 0.2625 × 158.04
Mass of KMnO₄ = 41.49 g
C. Determination of the mass of KMnO₄
We'll begin by determining the number of mole of KMnO₄ in the solution. This can be obtained as follow:
Volume = 80 mL = 80/1000 = 0.08 L
Molarity = 0.01 M
Mole of KMnO₄ =?
Mole = Molarity × Volume
Mole of KMnO₄ = 0.01 × 0.08
Mole of KMnO₄ = 0.0008 mole
Finally, we shall determine the mass of KMnO₄. This can be obtained as follow:
Mole of KMnO₄ = 0.0008 mole
Molar mass of KMnO₄ = 158.04 g/mole
Mass of KMnO₄ =?
Mass = mole × molar mass
Mass of KMnO₄ = 0.0008 × 158.04
Mass of KMnO₄ = 0.13 g
A worker gets paid 11.33 $/hour. The worker works on average 39.7 hours/week for 48 weeks per year. How much does the worker make in 1.7 years?
Answer:
36704 $
Explanation:
First we calculate how much the worker gets paid in one week:
11.33 $/hour * 39.7 hour/week = 449.80 $/weekThen we calculate how many weeks does the worker work in 1.7 years:
48 week/year * 1.7 years = 81.6 weeksFinally we calculate how much does the worker make in 1.7 years:
449.80 $/week * 81.6 weeks = 36704 $20. What is an irreversible change?
Answer:
A change is called irreversible if it cannot be changed back again. For example you cannot change a cake back into its ingredients again. Irreversible changes are permanent.
Explanation:
Hope this helps!! :))
It took 2.30 minutes using a current of 3.00 A to plate out all the copper from 0.300 L of a solution containing Cu2 . What was the original concentration of Cu2
Answer:
7.16 × 10⁻³ M
Explanation:
Let's consider the reduction reaction of copper during the electroplating.
Cu²⁺(aq) + 2 e⁻ ⇒ Cu(s)
We can calculate the moles of Cu²⁺ present in the solution using the following relations.
1 A = 1 C/s.1 min = 60 s.1 mole of electrons has a charge of 96486 C (Faraday's constant).1 mole of Cu²⁺ is reduced when 2 moles of electrons are gained.The moles of Cu²⁺ reduced are:
[tex]2.30 min \times \frac{60s}{1min} \times \frac{3.00C}{s} \times \frac{1mole^{-} }{96486C} \times \frac{1molCu^{2+} }{2mole^{-} } = 2.15 \times 10^{-3} molCu^{2+}[/tex]
[tex]2.15 \times 10^{-3} moles[/tex] of Cu²⁺ are in 0.300 L of solution.
[Cu²⁺] = 2.15 × 10⁻³ mol/0.300 L = 7.16 × 10⁻³ M
13. What does the Law of Conservation of Mass state?
Having enough folic acid in your system by the early weeks of pregnancy is critical to prevent spina bifida.
Answer:
Yes.
Explanation:
Yes, enough folic acid in the body by the early weeks of pregnancy helps to prevent spina bifida. The body of woman uses folate during the pregnancy which produces red and white blood cells that help your baby to grow. Folate also lowers the risk of neural tube defect (NTD) in the unborn baby. Neural tube defect (NTDs) are the serious birth defects that greatly affect the spinal cord, brain and skull of the baby.
What are fluids? Why are they so called?
Fluids are liquid and gases. They take the shape of their containers. They are called fluids because of their ability to flow.
Which of the following explains the high boiling
point of water?
a Surface tension
b Polarity
C Capillary action
d Hydrogen bonding
Answer:
The correct answer is - d. hydrogen bonding.
Explanation:
Water has strong hydrogen bonds between its molecules that require a very high amount of energy in order to break. Water molecules are joined together or bound with a strong intermolecular force called hydrogen bonds.
These bonds require more kinetic energy which means more temperature or heat in order to break the bonds and turn into steam and this is the reason it has a high boiling point.
12. Which formula shows a substance that is not molecular?
H₂
H2O
н
CO2
Answer:
the answer is H ..............
Describe the three freezing points. Is there a relationship between the amount of solute in the solution and the freezing temperature
Answer:
The three freezing points will all be slightly different. It is given that a water solution has a freezing point of zero degrees Celsius, so water would have a freezing temperature below that. Salt will lower the freezing point, the more that is added.
Explanation:
(a) Describe the process by which Nitrogen is obtained from air on a large scale
The element nitrogen exists as a gas and is obtained from air on a large scale by fractional distillation of air.
What is an element?An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
Learn more about element,here:
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When using vacuum filtration to separate a dissolved solid from an undissolved solid, what techniques should you use to ensure a quantitative separation
Answer: See explanation
Explanation:
Vacuum filtration is referred to as a fast filtration technique that is used in the separation of solids from liquids. It is also used to collect a desired solid. It basically uses a side-arm flask and a Buchner funnel.
Based on the question, the techniques that should be used to ensure a quantitative separation goes thus:
• Wet the filter paper before the mixture is poured into the filter funnel.
• Then, carefully rinse the flask with a little amount of water into the filter funnel.
• After that, the solid on the filter paper should be washed the with a small amount of water.
• Finally, Dry the solid on the filter paper when the separation is done.
someone answer please
Answer:
A
Explanation:
Which compound is insoluble in water?
Answer:
The answer is C... I am almost positive.
A 3.06 gram sample of an unknown hydrocarbon with empirical formula CH2O was found to contain 0.0170 moles of the substance. What are the molecular mass and molecular formula, respectively, of the compound
Answer:
180 amu
C₆H₁₂O₆
Explanation:
Step 1: Determine the molecular mass of the compound
The sample has a mass (m) of 3.06 g and it contains (n) 0.0170 moles. The molar mass M is:
M = m/n = 3.06/0.0170 mol = 180 g/mol
Then, the molecular mass is 180 amu.
Step 2: Determine the molar mass of the empirical formula.
M(CH₂O) = 1 × M(C) + 2 × M(H) + 1 × M(O)
M(CH₂O) = 1 × 12 g/mol + 2 × 1 g/mol + 1 × 16 g/mol = 30 g/mol
Step 3: Determine the molecular formula
First, we will determine "n" according to the following expression.
n = molar mass molecular formula / molar mass empirical formula
n = 180 g/mol / 30 g/mol = 6
The molecular formula is:
n × CH₂O = 6 × CH₂O = C₆H₁₂O₆
What are the laws and calculations governing gas behavior?
Answer:
Laws governing gas behavior.
Explanation:
Boyle's law:
It relates the pressure and volume of an ideal gas at a constant temperature.
According to this law:
"The volume of a fixed amount of gas at constant temperature is inversely proportional to its pressure".
[tex]P \alpha V[/tex].
Charle's law:
It relates the volume and absolute temperature of an ideal gas at a constant pressure.
According to this law:
"The volume of a fixed amount of gas at constant pressure is directly proportional to its absolute temperature".
[tex]V \alpha T[/tex].
Avogadro's law:
According to this law:
equal volumes of all gases under the same conditions of temperature and pressure contain, an equal number of moles.
[tex]V \alpha n[/tex].
Ideal gas equation:
By combining all the above-stated gas laws, this equation is formed as shown below:
[tex]V \alpha \frac{nT}{P} \\=> V= R. nT/ P\\=>PV=nRT[/tex]
R is called universal gas constant.
It has a value of 0.0821L.atm.mol-1.K-1.
Answer:
Boyle's law, Charle's law, Guy Lussac's law and Avogadro's law
Explanation:
All the gases behaves similarly when the environment conditions are normal. But when the physical condition changes like when the pressure, volume or temperature changes, the gas behaves differently and shows a deviation.
The number of gas laws are :
Boyle's Law
Boyle's law states that when the temperature remaining constant, the pressure of the gas varies inversely to the volume of the gas.
i.e. [tex]P \propto \frac{1}{V}[/tex]
Charle' law
Charle's law states that when pressure is constant, the temperature of a gas is directly proportional to the volume.
i.e. , [tex]$T \propto V$[/tex]
Gay Lussac's law
Gay - Lussa law states the volume and the mass of the pressure of the gas is directly proportional to the temperature of the gas.
i.e. P.T = constant
Avogadro's law
It states that under the conditions of same pressure as well as temperatures, the gases having equal volumes will have same numbers of molecules.
i.e. [tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex] = constant